Punjab National Bank [PNB] — Refund not credited

I've done online shopping from meripustak.com with my pnb rupay debit card but due to unavailability of the item, they cancelled my order. When i asked them about refund, they said that they've already refund the amount and provided me with the reference number. The amount is struck with the acquirer bank.

Here are the details :
Refund amount : rs. 950
Refund id: 20200911111212801300168451982388585
Refund reference id : de2564aa38854e1e92bfefe5724a1f4e
Refund date11 sep, 05:49 pm
Refund settlement date14 sep, 12:00 am